I belive Lou Budd covers much of that in OUR MARK TWAIN, but I may be
misremembering.
A book I read last year that I liked a lot, and which left an impression
along these lines, (but featuring another writer, albeit with some stuff on
MT as well), was:
Walt Whitman and the Culture of American Celebrity. By David Haven Blake.
New Haven: Yale University Press, 2006. xv, 251. $35.00.
-hb
Harold K. Bush, Ph.D
Saint Louis University